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When replacing an original electrical fuel pump , what type of pressure a new pump should deliver? The facet fuel pumps come in 4 to 5 psi (gold flow) and a lower pressure one 2.75 to 4 PSI. I would be tempted to go for the lower pressure pump as to avoid any leaks on the pressure regulator..has anyone had satisfactory use with the lower pressure pump facet 88 sold by international auto parts?
Herve
 

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The original fuel pump was a Bendix #476-474, which often is substituted by the #476-087 that was used on Porsche 911 (delivering 4-5 PSI @ 30 Gallons per hour). The 2600 SZ used twinned (parallel) fuel pumps (same pressure but twice the flow).

I don't recall ever seeing pressure and flow specs for the original pump. If anybody has them, please post them!
 

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Hi Herve,

You will want to use the lower pressure version. I believe it is Facet p/n 477060E. I recently installed one of these on a BMW 2002 and it seems to work perfectly. I measured the output pressure at just under 4 psi, which is the ideal pressure for the DCOE carbs. My experience with Solex carbs indicates that the lower the pressure the better, due to poor sealing of the inlet needle/seats, which results in excess fuel dribbling in the manifold and elsewhere. This pump is available from many sources. I walked into my local Napa Auto Parts and walked out with one in my hand (Napa p/n 610-1075, you can look this up on Napa's web site). I paid a bit of a premium there but I was pressed for time. Napa also has the internal filter replacement kits and soft mounts available on special order. I do not know if the filter fits the vintage Bendix pumps. It might since these are a direct descendant.

Steve
 

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Discussion Starter #4
alfa 2600 fuel pump

This BB is such a useful tool..thanks for your great advice and infos.. I will order a low pressure pump. I still have an original one that is working, but since I am restoring the car I think it is wise to change the pump that is after all 46 years old even if it has only 30,000 miles on the clock..
I have one more question regarding this pumps. They come with 1/4 NPT and 1/8NPT inlets. Dos anyone knows what the original pump inlet and outlet size was? I intend to have the original hoses reproduced using the original fittings.
Herve
 

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from the factory shop manual page 55: Outlet pressure = 75mm Hg (2.9 in. Hg); delivery = 60 - 70 lt/hr (15.9 -18.1 gph US)
Thanks for pointing out where the specs are listed (the page below is from the CarDisc DVD). The specs translates to 1.45 PSI.

So, on one hand this would indicate the pump used on Porsche 911 may to be too strong, but on the other hand, they twinned the pump on the 2600 SZ, which indicates the pressure may have dropped too low in high-flow conditions.
 

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Fuel pump

Either go for originallity/standard spec as listed in posts above

or as I have fit larger Gold top fuel pump with larger fuel lines/fittings plus a filter king or similar fuel pressure regulator. Set regulator pressue to specified level on as specs listed.

Especially on Solexes this will prevent fuel being pushed through the carbs when the engine is off but ignition on.

There is a horror story somewhere on the boards where someone left his radio and fuel pump on while washing his car. Fuel pumped past a float needle valve and filled the bores and sump with petrol , when he tried to start the car it blew out all the seals and wrecked the rings - lucky it didn't explode!

I have fitted an isolator switch for the fuel pump also as it is live always with ignition on..

The twin pump system for the SZ is on a technical buletin sheet on the cardisc CD - this can only have been implemented because of poor fuel feed with the smaller pump.
 
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